General Motors Corp. (GM) and Toyota Motor Co. (search) had the top vehicles in 15 of 18 categories in a closely watched survey of 2005 models released Wednesday by research firm J.D. Power and Associates (search). Toyota's Lexus SC430 (search) was the highest-ranking vehicle for the second year in a row. Owners of the luxury sedan reported 54 problems per 100 vehicles, less than half the industry average of 118 problems per 100 vehicles. Suzuki Motor Corp. (search) had the highest rate of problems per vehicle at 151 per 100 vehicles.